Display control device,  program for implementing the display control device, and recording medium containing the program

ABSTRACT

A virtual plane including a display screen is divided into small regions. If calculated coordinates of an intersection is located in one of the small regions outside the display screen, an icon corresponding to the small region is displayed at a predetermined position. If coordinates of the intersection are not calculated, an icon corresponding to the small region in which the preceding intersection coordinates were located in is displayed at a predetermined position.

TECHNICAL FIELD

The present invention relates to a controlling device for displaying acursor on a display screen, and specifically to a display controllingdevice for notifying that the cursor is out of the display screen whenthe cursor is not positioned inside the display screen, a program forimplementing such a display controlling device, and a recording mediumstoring such a program.

BACKGROUND ART

Conventionally, in video game machines or computers, an icon or aposition on the display screen is pointed by moving a cursor on thescreen with direction keys, a mouse or the like (hereinafter, referredto as “conventional cursor moving means”). The cursor is moved asfollows: The direction and the amount of movement of the cursor areinput through the conventional cursor moving means and detected everypredetermined period. The cursor display position is moved to a locationwhich is obtained by adding the amount of movement regarding thedirection of the movement to the current cursor display position.

FIG. 14 illustrates a method of moving the cursor with a mouse. Bymovement of a mouse from a position 802 to a position 802′, a cursor 801moves. If it is supposed that the amount (ΔX, ΔY) of the movement of thecursor is input through the mouse 802, the display position (X, Y) ofthe cursor 801 moves to a display position (X+ΔX, Y+ΔY).

Another cursor moving method developed recently uses a pointing deviceto point a position on the display screen directly. The pointing devicecaptures the image of the display screen with an imaging sensor, such asa CCD camera, mounted to the tip thereof, and outputs information aboutwhere in the image captured by the imaging sensor the certain light fromthe light emitting body mounted above or around the display screen ispositioned. In this cursor moving method, the cursor is moved asfollows: The intersection of the optical axis extending from the centralpoint of the imaging sensor to the display screen in the direction ofthe normal line and the display screen is calculated from theinformation output from the pointing device. The cursor is displayed atthe position of the intersection. In this way, the cursor is moved tofollow changes of the direction pointed by the pointing device.

FIG. 15 illustrates the method of moving the cursor by using thepointing device. By change of the direction from that pointed by thepointing device 803 to that pointed by the pointing device 803′, thecursor 801 on a display screen 800 moves from a display position (X, Y)to a display position (X′, Y′).

A method of calculating the cursor display position (the intersection ofthe optical axis of the imaging sensor and the display screen) with apointing device is disclosed in JP-A-8-226793, for example. In thismethod, infrared spots are displayed at the left and right edges of thedisplay screen. A CCD camera provided at a tip of an imitated guncaptures an image. The position shot by the imitated gun on the displayscreen is detected based on the position of the infrared spots in thecaptured image.

Patent Document 1: JP-A-8-226793

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, in the cursor moving method using the pointing device,coordinates of the cursor display position is determined and then thecursor is displayed at the coordinates. Therefore, if the coordinates ofthe display position is out of the display screen, the cursor is notdisplayed on the display screen because the cursor is treated as beinglocated out of the display screen.

For example, if the direction indicated by the pointing device 803 ischanged to a direction indicated by a pointing device 803″ as shown inFIG. 15, the cursor is not displayed on the display screen because thecursor is treated as being at a display position (X″, Y″). In this case,the user does not understand why the cursor is not displayed and whatmakes the cursor displayed, and is perplexed. Such a situation isdisadvantageous in particular if the user is required to make a quickselection during playing the game.

In the method using conventional cursor moving means, relative amountregarding the current cursor display is input through the conventionalcursor moving means, and the cursor is moved by this amount. Therefore,if the movement of the cursor is limited within the display screen, thecursor does not move out of the display screen. Accordingly, it iscritical to the user accustomed to the conventional cursor moving meansthat the cursor is not displayed on the display screen.

The present invention has been proposed under the above-describedcircumstances, and it is an object of the present invention to provide adisplay controlling device for notifying that the cursor is moved out ofthe display screen or for notifying the direction in which the cursor ismoved out from the display screen when the cursor is not displayed onthe display screen.

Means for Solving the Problems

According to the first aspect of the present invention, there isprovided a display controlling device comprising: a display unit fordisplaying an image; an input unit at which a signal is input, thesignal being output from an operation unit, the operation unit includingan imaging sensor for capturing a light image, the signal being based onan image captured by the imaging sensor, the operation unit beingarranged for a user to hold and operate, the light image being emittedfrom a light emitter toward front of a display screen of the displayunit, the light emitter being provided in a periphery of the displayscreen; an intersection position acquirer for acquiring, everypredetermined period, information about a position of an intersectionbased on the signal input at the input unit, the intersection beingproduced by a plane including the display screen of the display unit andone of a region including an optical axis of the imaging sensor and aregion including an axis substantially parallel to the optical axis; adeterminer for determining, every predetermined period, whether theintersection is located inside the display screen of the display unitbased on the information about the position of the intersection acquiredby the intersection position acquirer; a cursor displayer for displayinga cursor at the position of the intersection on the display screen ofthe display unit if the determiner determines that the intersection islocated inside the display screen; and a first notification controllerfor notifying that the cursor is located outside the display screen witha first notifier if the determiner determines that the intersection isnot located inside the display screen.

Preferably, the intersection position acquirer has an orthogonalcoordinate system defined in a virtual plane including the displayscreen, and acquires coordinates of the intersection in the orthogonalcoordinate system as information about the position of the intersection.The determiner determines whether the intersection is located inside thedisplay screen of the display unit using the coordinates of theintersection acquired by the intersection position acquirer.

Preferably, the intersection position acquirer can acquire thecoordinates of the intersection in a prescribed region outside thedisplay screen in the virtual plane. The determiner acquires theposition of the intersection outside the display screen using thecoordinates of the intersection acquired by the intersection positionacquirer if the determiner determines that the intersection is locatedoutside the display screen of the display unit. The first notificationcontroller notifies the position of the intersection outside the displayscreen acquired by the determiner with the first notifier.

Preferably, the display controlling device further comprises a storageunit for storing information about the position of the intersectionacquired by the intersection position acquirer. The determiner presumesthe position of the intersection outside the display screen based on thecoordinates of the preceding intersection acquired by the intersectionposition acquirer if the determiner determines that the intersection islocated outside the display screen of the display unit and if theintersection position acquirer has not been able to acquire thecoordinates of the intersection, the coordinates being stored in thestorage unit. The first notification controller notifies the position ofthe intersection outside the display screen with the first notifier, theposition being presumed by the determiner.

Preferably, the virtual plane outside the display screen is divided intoa plurality of small regions. The first notification controllerincludes: a judgment unit for judging which one of the plurality thesmall regions the coordinates of the intersection acquired by theintersection position acquirer are located in; and an image displayerfor memorizing information indicating the position of the intersectioncorresponding to each of the small regions, determining informationcorresponding to a judgment result of the judgment unit from theinformation, and displaying determined information on the display screenof the display unit.

Preferably, the virtual plane outside the display screen is divided intotwo large regions outwardly of the screen, and the intersection positionacquirer cannot acquire the coordinates of the intersection in oneregion outside, and the other region inside is divided into a pluralityof regions, and the virtual plane inside the display screen is dividedinto a plurality of small regions. The intersection position acquireracquires the coordinates of the intersection as information about theposition of the intersection if the intersection is located in the otherregion inside, and acquires that there are no coordinates of theintersection as information about the position of the intersection ifthe intersection is located in the one region outside. The firstnotification controller includes: a storage unit for storing informationabout the position of the intersection acquired by the intersectionposition acquirer every predetermined period; a judgment unit forjudging which one of the plurality of the small regions in the otherregions inside the intersection is located in based on the coordinatesif the information about the position of the intersection acquired bythe intersection position acquirer is the coordinates of intersection,and for judging which one of the plurality of small regions in the otherregion inside and the plurality of small regions inside the displayscreen the intersection is located in based on the coordinates of thepreceding intersection acquired by the intersection position acquirerand stored in the storage unit if the information about the position ofthe intersection is that there are no coordinates of the intersection;and an image displayer for memorizing information indicating theposition of the intersection corresponding to each of the small regions,determining the information corresponding to a judgment result of thejudgment unit from the information, and displaying determinedinformation on the display screen of the display unit.

Preferably, the image displayer has a table in which icons correspondingto each of the small regions are set, and determines an iconcorresponding to the judgment result of the judgment unit with referenceto the table, and displays the icon at a prescribed position on thedisplay screen of the display unit.

Preferably, display positions on the display screen of the display unitcorresponding to each of the small regions are set in the table. Theimage displayer displays the icon at the display position correspondingto the judgment result of the judgment unit set in the table as theprescribed position.

Preferably, the small regions includes at least eight regions eachlocated in one of up, down, right, left, right oblique and left obliquedirections.

Preferably, the display controlling device further comprises a timemeasurer for measuring time period during which the intersectionposition acquirer is not able to acquire the coordinates of theintersection; and a second notification controller for notifying thatthe position of the cursor is unclear with a second notifier if a timeperiod measured by the time measurer become longer than a prescribedtime period.

According to the second aspect of the present invention, there isprovided a program driving a computer provided with a display device tofunction as: an input unit at which a signal is input, the signal beingoutput from an operation unit, the operation unit including an imagingsensor for capturing a light image, the signal being based on an imagecaptured by the imaging sensor, the operation unit being arranged for auser to hold and operate, the light image being emitted from a lightemitter toward front of a display screen of the display device, thelight emitter being provided in a periphery of the display screen; anintersection position acquirer for acquiring, every predeterminedperiod, information about a position of an intersection based on thesignal input at the input unit, the intersection being produced by aplane including the display screen of the display device and one of aregion including an optical axis of the imaging sensor and a regionincluding an axis substantially parallel to the optical axis; adeterminer for determining, every predetermined period, whether theintersection is located inside the display screen of the display devicebased on the information about the position of the intersection acquiredby the intersection position acquirer; a cursor displayer for displayinga cursor at the position of the intersection on the display screen ofthe display device if the determiner determines that the intersection islocated inside the display screen; and a first notification controllerfor notifying that the cursor is located outside the display screen witha first notifier if the determiner determines that the intersection isnot located inside the display screen.

Preferably, the intersection position acquirer has an orthogonalcoordinate system defined in a virtual plane including the displayscreen, and acquires coordinates of the intersection in the orthogonalcoordinate system as information about the position of the intersection.The determiner determines whether the intersection is located inside thedisplay screen of the display device using the coordinates of theintersection acquired by the intersection position acquirer.

Preferably, the intersection position acquirer can acquire thecoordinates of the intersection in a prescribed region outside thedisplay screen in the virtual plane. The determiner acquires theposition of the intersection outside the display screen using thecoordinates of the intersection acquired by the intersection positionacquirer if the determiner determines that the intersection is locatedoutside the display screen of the display device. The first notificationcontroller notifies the position of the intersection outside the displayscreen acquired by the determiner with the first notifier.

Preferably, the program further drives the computer to function as astorage unit for storing information about the position of theintersection acquired by the intersection position acquirer. Thedeterminer presumes the position of the intersection outside the displayscreen based on the coordinates of the preceding intersection acquiredby the intersection position acquirer and stored in the storage unit ifthe determiner determines that the intersection is located outside thedisplay screen of the display unit and if the intersection positionacquirer has not been able to acquire the coordinates of theintersection. The first notification controller notifies, through thefirst notifier, the position of the intersection located outside thedisplay screen and presumed by the determiner.

Preferably, the virtual plane outside the display screen is divided intoa plurality of small regions. The first notification controllerincludes: a judgment unit for judging which one of the plurality thesmall regions the coordinates of the intersection acquired by theintersection position acquirer are located in; and an image displayerfor memorizing information indicating the position of the intersectioncorresponding to each of the small regions, determining informationcorresponding to a judgment result of the judgment unit from theinformation, and displaying determined information on the display screenof the display device.

Preferably, the virtual plane outside the display screen is divided intotwo large regions outwardly of the screen, and the intersection positionacquirer cannot acquire the coordinates of the intersection in oneregion outside, and the other region inside is divided into a pluralityof regions, and the virtual plane inside the display screen is dividedinto a plurality of small regions. The intersection position acquireracquires the coordinates of the intersection as information about theposition of the intersection if the intersection is located in the otherregion inside, and acquires that there are no coordinates of theintersection as information about the position of the intersection ifthe intersection is located in the one region outside. The firstnotification controller includes: a storage unit for storing informationabout the position of the intersection acquired by the intersectionposition acquirer every predetermined period; a judgment unit forjudging which one of the plurality of the small regions in the otherregions inside the intersection is located in based on the coordinatesif the information about the position of the intersection acquired bythe intersection position acquirer is the coordinates of intersection,and for judging which one of the plurality of small regions in the otherregion inside and the plurality of small regions inside the displayscreen the intersection is located in based on the coordinates of thepreceding intersection acquired by the intersection position acquirerand stored in the storage unit if the information about the position ofthe intersection is that there are no coordinates of the intersection;and an image displayer for memorizing information indicating theposition of the intersection corresponding to each of the small regions,determining the information corresponding to a judgment result of thejudgment unit from the information, and displaying determinedinformation on the display screen of the display device.

Preferably, the image displayer has a table in which icons correspondingto each of the small regions are set, and determines an iconcorresponding to the judgment result of the judgment unit with referenceto the table, and displays the icon at a prescribed position on thedisplay screen of the display device.

Preferably, display positions on the display screen of the displaydevice corresponding to each of the small regions are set in the table.The image displayer displays the icon at the display positioncorresponding to the judgment result of the judgment unit set in thetable as the prescribed position.

Preferably, the small regions includes at least eight regions eachlocated in one of up, down, right, left, right oblique and left obliquedirections.

Preferably, the program drives the computer to further function as atime measurer for measuring time period during which the intersectionposition acquirer is not able to acquire the coordinates of theintersection; and a second notification controller for notifying thatthe position of the cursor is unclear with a second notifier if a timeperiod measured by the time measurer become longer than a prescribedtime period.

According to the third aspect of the present invention, there isprovided a recording medium storing the program according to the secondaspect of the present invention. The recording medium is readable by acomputer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of home video game machine which includes adisplay controlling device according to the present invention.

FIG. 2 shows a virtual plane which includes a display screen and isdivided into a plurality of regions.

FIG. 3 is a table which shows ranges of regions 1 through 8.

FIG. 4 is a table which shows icon direction and icon coordinatesassigned for each of the regions.

FIG. 5 is a diagram for describing cursor movement instruction iconsmatched with the icon directions in FIG. 4.

FIG. 6 shows an example of the cursor movement instruction iconsdisplayed when calculated intersection coordinates fall in a region 1.

FIG. 7 is a table which shows ranges of regions 1′ through 8′.

FIG. 8 is a block diagram showing an internal configuration of the gamemachine 1.

FIG. 9 is a block diagram showing an internal configuration of anoperation controller 2.

FIG. 10 is a main flowchart of a cursor display operation.

FIG. 11 is a flowchart showing a first display operation of cursormovement instruction icon.

FIG. 12 is a flowchart showing a second display operation of cursormovement instruction icon

FIG. 13 is a diagram for describing a second embodiment.

FIG. 14 is a diagram for describing how a cursor may be moved by using amouse.

FIG. 15 is a diagram for describing how a cursor may be moved by using apointing device.

BEST MODE FOR CARRYING OUT THE INVENTION

A first preferred embodiment of the present invention, in the form of ahome video game machine with an operation controller functioning as apointing device, will be described with reference to the drawings below.

FIG. 1 shows an example of a home video game machine which includes adisplay controlling device according to the present invention. The gamemachine 1 is a video game machine for home use which enables the user toenjoy the game. Game programs and game data are recorded in a DVD-ROM(Digital Versatile Disc-ROM). The game programs and game data stored inthe DVD-ROM dropped in the DVD-ROM drive is loaded to a memory (RAM) inthe game machine 1. The game machine 1 causes the CPU (CentralProcessing Unit) to execute the game programs, allowing the user toenjoy the game. The game machine 1 is connected with a display device 3having a display screen 31, such as a television set, and a lightemitting device 4 which is placed on the display device 3 and providedwith light emitting lamps 41, 42. An operation controller 2 performsshort range wireless communications with the game machine 1 via atransmission antenna 22 and a receiving antenna 11 provided in the gamemachine 1.

The operation controller 2 transmits signals inputted with an operationbutton 23, measurement values received from various sensors which arenot illustrated, and so on as information for playing the game. Also,the operation controller 2 functions as a pointing device, and transmitsthe information of the position of the light emitted from the lightemitting device 4 in the image captured by the imaging sensor 21, suchas a CCD, provided at the tip to the game machine. If the light emittingdevice 4 is out of capturing region of the imaging sensor 21 and hencethe imaging sensor 21 is not able to capture the light emitted from thelight emitting device 4, information of light capture failure istransmitted. The information obtained from the image captured by theimaging sensor 21 and transmitted from the operation controller 2 willbe referred to as image capture information.

From information received from the operation controller 2 about lightemitted from the light emitting device 4, the game machine 1 calculatesthe position of intersection (“hereinafter referred to as “intersectionposition”) of the optical axis extending from the central point of theimaging sensor 21 of the operation controller in the normal directionand the display screen 31 of the display device. The intersectionposition to be calculated is different from the accurate position of theintersection of the optical axis of the imaging sensor 21 and the planeincluding the display screen 31 because it includes a small amount oferror. However, this is not a problem in playing the game because thecursor is moved in accordance with change of the orientation of theoperation controller 2, and excessive accuracy is not required. If thecalculated intersection position is inside the display screen 31, thecursor is displayed at the calculated position on the display screen 31.On the other hand, if the calculated intersection position is outsidethe display screen 31, it is determined in which direction the cursor ismoved out of the display screen based on which one of a plurality ofdivisional regions outside the display screen 31 the calculated positionis located at. Then, an icon (hereinafter referred to as “cursormovement instruction icon”) is displayed near the position where thecursor has moved out of the display screen 31 to request the user ofmoving the cursor back to inside the display screen 31.

If the game machine 1 is not able to calculate the intersection positiondue to reception of the information from the operation controller 2 thatthe game machine could not capture the light emitted from the lightemitting device 4, the game machine 1 estimates the direction in whichthe cursor has moved out from the preceding position of the cursor.Specifically, the game machine 1 estimates the direction in which thecursor has moved out of the display screen based on which one of thedivisional regions, inside and outside the display screen 31, thecalculated preceding intersection position is located at, and thendisplays a cursor movement instruction icon near the position where thecursor has presumably moved out of the display screen 31. Here, forrequesting the user to move the cursor back from where the cursor hasmoved out to inside the display screen 31, the cursor movementinstruction icon has a shape for indicating the reverse direction to thedirection in which the cursor has moved out. Alternatively, fornotifying the user the direction in which the cursor has moved out, theicon may have a shape for indicating the direction in which cursor hasmoved out.

Display operation based on the calculated intersection position isdescribed below.

FIG. 2 illustrates a plurality of regions into which a virtual planeincluding the display screen 31 is divided based on coordinates in anorthogonal coordinate system defined in the plane. This coordinatesystem defines the center of the display screen 31 as (0, 0), theright-hand direction of the display screen 31 as the positive directionof X axis, and the downward direction of the display screen 31 as thepositive direction of Y axis. Further, the right edge, the left edge,the lower edge, and the upper edge of the display screen 31 isrepresented as X=Xa, X=−Xa, Y=Ya, and Y=−Ya, respectively. In FIG. 2, aregion within heavy lines, which is represented as −Xa≦X≦Xa and−Ya≦Y≦Ya, corresponds to the inside of the display screen 31. Theintersecting point is calculated as coordinates (hereinafter referred toas “intersection coordinates”) in this coordinate system.

When calculated intersection coordinates (X, Y) are within the range of−Xa≦X≦Xa and −Ya≦Y≦Ya, that is, when the intersection coordinates areinside the display screen 31, the cursor is displayed at a region whosecentral point is the intersection coordinates. In an actual operation,the cursor image is depicted on the display screen 31 with the centralpoint being coordinates on the display screen 31 corresponding to theintersection coordinates. For example, if it is supposed that thedisplay screen 31 is constituted of 640 pixels×448 pixels, and the upperleft corner of the screen represents the position (0, 0), intersectioncoordinates (0, 0) correspond to coordinates (320, 224) on the displayscreen 31, and therefore a cursor image is depicted in the region whosecentral point is the above-described coordinates.

As shown in FIG. 2, the region outside of the display screen 31, whichis defined by X=−Xa, Xa, Y=−Ya, Ya, is divided into eight regions 1-8.FIG. 3 is a table which shows ranges of the respective regions. Itshould be noted here that the way the region is divided is not limitedto this, and more and smaller regions may be made by division. If thecalculated intersection coordinates is located in any one of theseregions, the cursor is not displayed on the display screen 31. In thiscase, the cursor movement instruction icon which is determined based onwhich region the intersection coordinates are located at is blinked onthe display screen 31 at the position determined based on that region(This blinking operation will be referred to as “the first displayoperation of the cursor movement instruction icon”). Such blinking isutilized for facilitating the user to be aware of the cursor movementinstruction icon. Alternatively, the cursor movement instruction iconmay be simply displayed if the size or the color thereof is so appealingthat the user can easily be aware of it.

FIG. 4 is a table showing directions of the cursor movement instructionicon displayed on the display screen 31 determined based on the regions1-8 which the intersection coordinates are located in, and also showingcentral coordinates (hereinafter, referred to as “icon coordinates”) ofthe region which the cursor movement instruction icon is displayed in.Each of the icon coordinates is set near an edge of the display screen31 within the respective one region. For example, icon coordinates (X1,Y1) is set to (30, 30) near the upper left corner of the display screen31 having the above-mentioned pixel arrangement. FIG. 5 illustrates thecursor movement instruction icon correspond to an icon direction shownin FIG. 4. The cursor movement instruction icon is constituted of acircle centered on the icon coordinates and a substantially triangularprojection projecting in the direction corresponding to the icondirection. The projection is provided so as to extend in the directioncorresponding to one of the icon directions shown in FIG. 4, which aredetermined at every step of 45° in the clockwise direction from theupward direction 0° in FIG. 5. For example, the projection extends tothe right side from the circle if the icon direction is 90°. Actually,the game data including image data of an icon image (pointing upward)shown in FIG. 5 and a table of icon direction and icon coordinates shownin FIG. 4 are loaded to a RAM from the DVD-ROM. Then, the image data ofthe icon image is rotated to an icon direction retrieved from the tablefor displaying. Alternatively, the table may contain a plurality ofimage data of icon images each of which corresponds to respective oneicon direction, instead of a plurality of icon directions.

For example, FIG. 6 shows an example of the displayed cursor movementinstruction icon in the case that the calculated intersectioncoordinates is located in the region 1. In this case, the cursormovement instruction icon 7 having a projection shown in FIG. 5extending the direction of 135° is blinked in the display regioncentered on the coordinates (X1, Y1) on the display screen 31. Thisnotifies the user that the cursor 6 has moved away in the upper leftdirection of the display screen 31, and the user is requested to bringthe cursor 6 back in the direction indicated by the projection of thecursor movement instruction icon 7 into the display screen 31.

Next, an operation (referred to as “the second display operation of thecursor movement instruction icon”) of displaying the cursor movementinstruction icon in the case that the intersection coordinates is notable to be calculated will be described below.

When it is impossible to calculate the intersection coordinates, theicon direction (icon image) and the icon coordinates are determinedbased on the calculated preceding intersection coordinates. A state inwhich the intersection coordinates are not able to be calculated tendsto occur by changing the direction pointed by the operational controller2 to a direction away from the display screen 31 from the arrangement inwhich the intersection coordinates are located in one of the regions 1-8(See FIG. 2.). Therefore, the cursor movement instruction iconcorresponding to the icon coordinates set in FIGS. 4 and 5 is blinkedbased on which one of the regions the calculated preceding intersectioncoordinates were located in.

A state in which the intersection coordinates are not able to becalculated can also occur by changing the direction pointed by theoperation controller 2 rapidly from the arrangement in which theintersection coordinates are located in the display screen 31. Since theoperation controller 2 transmits the image capture information at everyperiod of 1/30 second in the present embodiment, this state isestablished if the direction pointed by the operation controller 2 ischanged in the period of 1/30 second from within the display screen 31to a direction with which the intersection coordinates are not able tocalculated. In this case, the calculated preceding intersectioncoordinates are in a region which corresponds to the inside of thedisplay screen 31.

As shown in FIG. 2, the region which corresponds to the inside of thedisplay screen 31 is divided by X=−Xb, Xb, Y=−Yb, 0, Yb into eightregions 1′-8′. Xb and Yb are set as Xb=(⅓)Xa and Yb=(⅓)Ya so as totrisect the ranges −Xa≦X≦Xa and −Ya≦Y≦Ya, respectively. It is rare thata state in which the intersection coordinates are located near thecenter of the display screen 31 is changed into a state in which theintersection coordinates are not able to be calculated. Since thedisplay screen 31 has a horizontally long shape, it is more likely thatthe cursor moves out towards the upward or downward direction ratherthan towards the left or right direction. Therefore, the region isdivided into the region 2′ and the region 7′ contacting each other atthe center in the up and down direction in the present embodiment. FIG.7 is a table which shows a range for each of the regions. It should benoted here that the way the region is divided is not limited to this.For example, division may be made more finely into smaller regions.

If the calculated preceding intersection coordinates are located in anyof the regions 1′-8′ corresponding to the inside of the display screen31, the cursor movement instruction icon corresponding to the iconcoordinates set in FIGS. 4 and 5 is blinked based on the region.

The intersection coordinates are not able to be calculated also in thecase that an obstacle between the operation controller 2 and the lightemitting device 4 inhibits the operation controller from capturing thelight emitted by the light emitting device. In this case, the cursormovement instruction icon is displayed based on the calculated precedingintersection coordinates although there is no need to change thedirection pointed by the operation controller 2. However, this is notseverely problematic because the user is aware that the obstacle infront of him/her causes the display, and then moves the obstacles awayignoring the displayed cursor movement instruction icon.

Further, in the present embodiment, when the state in which theintersection coordinates are not able to be calculated continues for apredetermined period, since the cursor position is unclear (that is, itis not likely that the operation controller 2 actually points to theposition based on the calculated preceding intersection coordinates), awarning is displayed and audio guidance is made for requesting the userto change the direction of the operation controller 2 toward the displayscreen 31. In this way, the user is informed that the cursor position isunclear, and the user is requested to move the cursor back to within thescreen without notifying information about an unlikely situation (thatis, the position based on the calculated preceding intersectioncoordinates). The warning may be made by displaying an icon. However,for the purpose of notifying the user who has not become aware of thecursor movement instruction icon, it is better to use notifying meansother than an icon. The warning will also help the user become aware ofan issue in other situations such as when the user is not aware of anobject between the operation controller 2 and the light emitting device4, when the operation controller 2 is too close to the display screen31, and when the tip of the operation controller 2 is too dirty tocapture the beams from the light emitting device 4.

Next, hard ware configuration of the game machine 1 and the operationcontroller 2 will be described below.

FIG. 8 is a block diagram showing the internal configuration of the gamemachine 1. The game machine 1 includes a CPU 101, a RAM (Random AccessMemory) 102, a ROM (Read Only Memory) 103, a drawing data generationprocessor 104, a drawing operation processor 105, a VRAM (Video-RAM)106, a D/A (Digital-Analog) converter 107, an audio processor 108, anamplifier 109, a light emitting device controller 110, an operationsignal receiver 111, a DVD-ROM drive 112 and a bus 113.

The game machine 1 is connected with a television set. The displaydevice of the television set, such as a cathode ray tube or a liquidcrystal display, is used as the external display device 3 connected tothe D/A converter 107 whereas a speaker incorporated in the televisionset is used as an external speaker 5 connected to the amplifier 109.

The game machine 1 is also connected with the light emitting device 4via the light emitting device controller 110, and is provided with thereceiving antenna 11 connected to the operation signal receiver 111. Thelight emitting device 4 is controlled so as to emit light with the lightemitting lamps 41, 42. The information to calculate the above-describedintersection position is obtained from the position of the light emittedby the light emitting device 4 in the image captured by the imagecapturing sensor 21 of the operation controller. Further, the lightemitting device 4 utilizes infrared light having a wavelength out of thevisible region not to disturb operation by the user.

The CPU 101, the RAM 102, the ROM 103, the drawing data generationprocessor 104, the drawing operation processor 105, the audio processor108, the light emitting device controller 110, the operation signalreceiver 111 and the DVD-ROM drive 112 are connected with each other viathe bus 113 for mutual data transmission.

The CPU 101 controls the whole progress of the game by executing thegame program loaded to the RAM 102 from the DVD-ROM, as describedearlier. Specifically, when the operation controller 2 transmits asignal, the CPU 101 processes a prescribed game operation in accordancewith the signal under the game program. Further, the CPU 101 displaysthe process result in the form of a three-dimensional image on thedisplay device 3, and outputs the result as sound effects with thespeaker 5.

Processes of displaying the three-dimensional image on the displaydevice 3 is performed mainly by the drawing operation processor 105. TheCPU 101 determines the content of three-dimensional image to bedisplayed on the display device 3 based on the signal from the operationcontroller 2. The drawing data generation processor 104 generatesnecessary imaging data for the content. The drawing operation processor105 performs the processes of drawing in accordance with the transmittedimaging data. Further, the CPU 101 determines contents of sound effectsor BGM to be output from the speaker 5. The audio processor 108 producesaudio data corresponding to the audio contents, and drives the speaker 5to output the audio data via the amplifier 109.

Further, the CPU 101 performs control for displaying of the cursor andthe cursor movement instruction icon described above. In other words,the CPU 101 calculates the intersection coordinates from the imagecapture information received from the operation controller 2. Next, theCPU 101 determines which one of the regions the intersection coordinatesis located in, and displays the cursor or the cursor movementinstruction icon at a determined position. Further, the CPU 101 measuresthe term during which the intersection coordinates are not able tocalculated, and displays a warning and outputs sounds when a prescribedterm lapses.

The RAM 102 provides a storage area for game programs and game dataloaded from a DVD-ROM in the DVD-ROM drive 112 and a work area for theCPU 101 to execute the game programs. The game program and the game datanecessary to perform the game are read out from the DVD-ROM and thenstored in the RAM 102. The game data include tables (See FIGS. 3 and 7)for determining which one of the regions the intersection coordinatesare located in, icon images (See FIG. 5), tables (See FIG. 4) of iconcoordinates and so on, as described above. Further, the work areaprovides a region for storage and updating the intersection coordinates.

The ROM 103 stores a basic program which includes basic functions of thegame machine 1, such as disc loading function, and procedures to readingthe game program and the game data recorded in the DVD-ROM, and so on.The CPU 101 operates the DVD-ROM drive 112 in accordance with the basicprogram stored in the ROM 103 when a DVD-ROM is dropped on the DVD-ROMdrive 112. The CPU 101 loads game programs and game data from theDVD-ROM to the RAM 102, and makes settings to start the game.

The drawing data generation processor 104 performs various operationsnecessary for the drawing process. Based on image data from the RAM 102and operation information from the operation controlling device 2, thedrawing data generation processor 104 calculates data necessary fordrawing, and supplies the calculation results to the drawing operationprocessor 105.

The drawing operation processor 105 generates images for each of theframes in three-dimensional image (two-dimensional images produced byperspective projection) and displays it on the display device 3. Thedrawing operation processor 105 produces a two-dimensional image of eachframe to display on the display device 3 using data supplied from thedrawing data generation processor 104 based on a drawing instructionfrom the CPU 101. In this process, an image of a cursor or of a cursormovement instruction icon is pasted on a predetermined position in thetwo-dimensional image according to need. The drawing operation processor105 is connected with the VRAM 106 for forming two-dimensional imagesfor each frame. The drawing operation processor 105 produces data of atwo-dimensional image of a frame at every 1/30 second period using theVRAM 106.

The D/A converter 107 converts image data output from the VRAM 106 intoanalog signals for outputting the signals to the display device 3.

The audio processor 108 reads audio data of sound effect or BGM out fromthe RAM 102, and performs a predetermined process and D/A conversion foroutputting to the amplifier 109. The amplifier 109 amplifies the audiosignals from the audio processor 108 at a predetermined gain and thenoutputs the signals to the speaker 5.

The light emitting device controller 110 controls the light emittingdevice 4 so as to emit light based on an instruction from the CPU 101.

The operation signal receiver 111 receives signals sent from theoperation controller 2 by short range wireless communication with thereceiving antenna 11. The signals from the operation controller 2include operation information regarding the operation button provided onthe operation controller 2, and measurement data from e.g. anacceleration sensor provided in the operation controller 2, imagecapture information, and so on. The user can play the game by thesesignals sent from the operation controller 2.

FIG. 9 is a block diagram showing the internal configuration of theoperation controller 2. The operation controller 2 includes a CPU 201, aRAM 202, a ROM 203, a position detecting unit 204, an operation signaltransmitting unit 205, and an operation unit 206.

The operation controlling device 2 is provided with an imaging sensor21, such as a CCD camera, connected to the position detecting unit 204,a transmission antenna 22 connected to the operation signal transmittingunit 205 and an operation button 23 connected to the operation unit 206.

The CPU 201, the RAM 202, the ROM 203, the position detecting unit 204,the operation signal transmitting unit 205 and the operation unit 206are connected with each other via the bus 207 for mutual datatransmission.

The CPU 201 controls the operation controller 2 based on controlprograms stored in the ROM 203. The RAM 202 provides a work area foroperation of the CPU 201. The ROM 203 stores the control programs forcontrolling the operation controller 2.

The position detecting unit 204 detects the positions of light emittedfrom the light emitting device in the image captured by the imagingsensor 21. The CPU 201 controls the operation signal transmitting unit205 to transmit image capture information, which is information aboutthe position of light if the position detecting unit 204 could detectthe position of light, or information that the position of light couldnot be detected if the position detecting unit 204 could not detect theposition of light.

The operation signal transmitting unit 205 transmits an operation signalfrom the operation unit 206, image capture information from the positiondetecting unit 204, and measurement data from e.g. an accelerationsensor, which is not illustrated, via the transmission antenna 22 byshort range wireless communication.

The operation unit 206 detects that the operation button 23 is pressedin the form of an operation signal. The operation button 23 is pressedto select an icon or an item on which the cursor is superimposed on thedisplay screen 31, or to specify a position on the display screen 31.The operation unit 206 detects this pressing of the operation button 23in the form of an operation signal. The operation signal transmittingunit 205 transmits the operation signal to the game machine 1. The gamemachine 1 performs a prescribed process (such as a process for theselected icon or item, or movement of a character to the specifiedposition) based on the received operation signal and the position of thecursor on the display screen 31.

Next, the procedures of displaying the cursor will be described belowwith reference to the flowcharts in FIGS. 10-12.

FIG. 10 is a main flowchart of a cursor display operation. Thisoperation is performed by the CPU 101 each time image captureinformation is sent from the operation controller 2.

After the image capture information is transmitted from the operationcontroller 2, the intersection coordinates are calculated (S1). Next, itis determined whether the intersection coordinates have beensuccessfully calculated (S2). If the intersection coordinates have beencalculated successfully (S2: YES), the intersection coordinates storedin the RAM 102 are updated with the calculated intersection coordinates(S3) for referencing next time if the intersection coordinates are notable to be calculated. Next, it is determined whether the timer formeasuring the time period of the state in which the intersectioncoordinates are not able to be calculated is in operation (S4). If thetimer is in operation (S4:YES), the timer is stopped (S5) for stoppingtime measurement because the intersection coordinates have beencalculated successfully.

Next, it is determined whether the intersection coordinates are locatedwithin the screen display 31 (S6). That is, it is determined whether theintersection coordinates (X, Y) are within the range of −Xa≦X≦Xa and−Ya≦Y≦Ya. If the intersection coordinates are inside the display screen31 (S6: YES), a cursor is displayed at the intersection coordinates(S7). If the intersection coordinates are not inside the display screen31 (S6: NO), the first display operation of the cursor movementinstruction icon is performed (S8). The first display operation ofcursor movement instruction icon will be described later.

If the intersection coordinates have not been calculated in step S2, itis determined whether the timer for measuring the time period of thestate in which the intersection coordinates are not able to becalculated is in operation (S9). If the timer is not in operation(S9:NO), operation of the timer is started (S10).

Next, it is determined whether the time period during which the timercontinues to measure time is longer than a predetermined time (S11). Ifthe time period is not longer than the predetermined time yet (S11: NO),the second display operation of the cursor movement instruction icon isperformed (S12). The second display operation of cursor movementinstruction icon will be described later. If the time period is longerthan the predetermined time (S11: YES), it is notified that the cursorposition is unclear (S13).

FIG. 11 is a flowchart showing the first display operation of cursormovement instruction icon.

First, it is determined which one of the regions 1-8 the intersectioncoordinates are located in with reference to the table (See FIG. 3.)stored in the RAM 102 (S21). Next, an icon image and icon coordinatesare obtained based on the table (See FIG. 4.) and the icon image (SeeFIG. 5.) stored in the RAM 102 (S23). Next, the icon image is displayedat the obtained icon coordinates on the display screen 31 (S23).

FIG. 12 is a flowchart showing the second display operation of cursormovement instruction icon.

First, the calculated preceding intersection coordinates are obtainedfrom the RAM 102 (S31). It is determined which one of the regions 1-8and 1′-8′ the intersection coordinates are located in with reference tothe tables (See FIGS. 3 and 7.) stored in the RAM 102 (S32). Next, anicon image and icon coordinates corresponding to the determined regionare obtained based on the table (See FIG. 4.) and the icon image (SeeFIG. 5.) stored in the RAM 102 (S33). Next, the icon image is displayedat the obtained icon coordinates on the display screen 31 (S34).

If the intersection coordinates are not calculated or the calculatedintersection coordinates are located outside of the display screen 31,the cursor movement instruction icon is displayed on the display screen31, as described above. Therefore, the user can be aware that the cursorhas moved out of the display screen 31, and move the cursor back toinside of the display screen 31 as instructed by the cursor movementinstruction icon. Further, if the intersection coordinates are notcalculated for a period longer than the predetermined time, the user iswarned to move the cursor back to inside. Therefore, even if the user isnot aware of the cursor movement instruction icon, such a warning canfacilitate the user to move the cursor back the inside of the displayscreen 31.

In this way, it is determined which direction the cursor has moved outbased on the region in which the intersection coordinates are locatedin, and the icon image is displayed on the position set in accordancewith the region in the first embodiment. However, the cursor movementinstruction icon may be displayed on a position calculated directly fromthe intersection coordinates, and the icon image may be produced basedon the calculated position.

FIG. 13 is a diagram for describing a second embodiment, in which aposition at which the cursor movement instruction icon is displayed iscalculated and an icon image is produced based on the intersectioncoordinates located outside the display screen. The second embodimentdiffers from the first embodiment in that the method to obtain theposition at which the cursor movement instruction icon is to bedisplayed and the icon image. Only this method will be described below.FIG. 13 shows an orthogonal coordinate system defined in a virtual planeincluding the display screen 31 similar to that of the first embodiment.Further, lines X=Xc, X=−Xc, Y=Yc and Y=−Yc are provided in the regioncorresponds to the display screen 31. The intersection of these linesand the line extending from the origin of the coordinate system to theintersection coordinates (Xp, Yp) provides the central point of theregion which the cursor movement instruction icon is displayed in. Xcand Yc are so set that the entirety of the cursor movement instructionicon in displayed inside the display screen 31, and the cursor movementinstruction icon is located not to cause an obstruction to the gameoperation. The icon image is constituted of a circle, centered on theintersection and having a predetermined radius, and a projectionprojecting from the circle toward the origin.

For example, if the intersection coordinates (Xp, Yp) are located in thefirst quadrant, the intersection of the line Y=(Yp/Xp)X and the lineY=Yc(0≦X≦Xc) or X=Xc(0≦Y≦Yc) is calculated. As shown in FIG. 13, if theintersection is located on the line Y=Yc(0≦X≦Xc), the intersection is((Xp/Yp)Yc, Yc). A circle centering on this intersection and aprojection projecting toward the origin are displayed in a proper regionon the display screen 31.

In this embodiment, if the cursor is not displayed in the display screen31, it is notified in which direction the cursor is moved out of thedisplay screen 31 by means of the icon image and the position which theicon image is displayed at. However, the direction may be notified tothe user only by changing the icon image with the cursor movementinstruction icon being displayed at a predetermined position such as thecenter of the screen. Further, the direction may be notified only bychanging the position where the icon image is displayed with the iconimage being kept unchanged. Further, means for notifying the directionin which the cursor has moved out is not limited to displaying the icon.The direction may be notified by displaying at text, sound, orcombination of them. Further, it may be notified only that the cursorhas moved out of the display screen 31, instead of which direction thecursor has moved in.

In describing the above embodiments, the display controlling deviceaccording to the present invention is, applied in a home game machine.However, the display controlling device according to the presentinvention is applicable to not only a home game machine, but also othertypes of game machines such as an arcade game machine. Further, thedisplay controlling device according to the present invention isapplicable to a portable game machine if the imaging sensor is mountedon a member fixed to the user's body, and the member is configured tofunction as a pointing device when the member is moved relatively to thedisplay screen provided with a light emitting device. Further, thedisplay controlling device according to the present invention isapplicable to machines other than a game machine for pointing theposition on the display screen 31 with a cursor being displayed on thedisplay screen.

In the embodiment above, information about the position of light emittedfrom the light emitting device 4 in the image captured by the imagingsensor 21 is transmitted to the game machine 1 as the image captureinformation. However, the intersection coordinates may be calculatedfrom the image capture information in the operation controller 2, andinformation about the calculated intersection coordinates or informationthat the intersection coordinates have not been calculated may betransmitted to the game machine 1. In this case, “signal based on theimage capture information of the imaging sensor” of the presentinvention is information about the calculated intersection coordinatesor information that the intersection coordinates have notbeen-calculated.

Further, the intersection coordinates may be obtained by means otherthan calculation from the image capture information from the imagingsensor 21 of the operation controller. For example, a plurality ofcameras provided near the display screen 31 may capture the image of theoperation controller 2, and the direction pointed by the operationcontroller 2 may be calculated from the three dimensional positions ofthe top and bottom tips of the operational controller 2, and theintersection coordinates may be obtained from the direction. Further,the orientation of the operation controller 2 relative to theorientation of the operation controller 2 pointing the center of thedisplay screen 31 may be determined from a acceleration sensor mountedtherein, and the direction pointed by the operation controller 2 may becalculated from the change of the orientation, and the intersectioncoordinates may be obtained from the direction. In this case, the changeof orientation is not detected if the operation controller 2 movesparallel with its orientation being kept unchanged. Therefore, lateralcursor movement has to be achieved by e.g. lateral rotation of theoperation controller 2.

In the embodiment above, the cursor is displayed at the position of theintersection of the optical axis of the imaging sensor 21 and the planeincluding display screen 31 of the display device 3. However, thedisplay controlling device according to the present invention is notlimited to this configuration. The cursor may be displayed at theposition of the intersection of an axis extending from one surface ofthe operation controller 2 in a prescribed direction and the planeincluding the display screen 31. Here, the surface of the operationcontroller 2 means the side surface provided with the imaging sensor 21,and the axis extending in a prescribed direction means an axis extendingsubstantially in parallel with the optical axis of the imaging sensor21.

1. A display controlling device comprising: a display unit fordisplaying an image; an input unit at which a signal is input, thesignal being output from an operation unit, the operation unit includingan imaging sensor for capturing a light image, the signal being based onan image captured by the imaging sensor, the operation unit beingarranged for a user to hold and operate, the light image being emittedfrom a light emitter toward front of a display screen of the displayunit, the light emitter being provided in a periphery of the displayscreen; an intersection position acquirer for acquiring, everypredetermined period, information about a position of an intersectionbased on the signal input at the input unit, the intersection beingproduced by a plane including the display screen of the display unit andone of a region including an optical axis of the imaging sensor and aregion including an axis substantially parallel to the optical axis; adeterminer for determining, every predetermined period, whether theintersection is located inside the display screen of the display unitbased on the information about the position of the intersection acquiredby the intersection position acquirer; a cursor displayer for displayinga cursor at the position of the intersection on the display screen ofthe display unit if the determiner determines that the intersection islocated inside the display screen; and a first notification controllerfor notifying that the cursor is located outside the display screen witha first notifier if the determiner determines that the intersection isnot located inside the display screen.
 2. The display controlling deviceaccording to claim 1, wherein the intersection position acquirer has anorthogonal coordinate system defined in a virtual plane including thedisplay screen, and acquires coordinates of the intersection in theorthogonal coordinate system as information about the position of theintersection; wherein the determiner determines whether the intersectionis located inside the display screen of the display unit using thecoordinates of the intersection acquired by the intersection positionacquirer.
 3. The display controlling device according to claim 2,wherein the intersection position acquirer can acquire the coordinatesof the intersection in a prescribed region outside the display screen inthe virtual plane; wherein the determiner acquires the position of theintersection outside the display screen using the coordinates of theintersection acquired by the intersection position acquirer if thedeterminer determines that the intersection is located outside thedisplay screen of the display unit; wherein the first notificationcontroller notifies the position of the intersection outside the displayscreen acquired by the determiner with the first notifier.
 4. Thedisplay controlling device according to claim 2, further comprising astorage unit for storing information about the position of theintersection acquired by the intersection position acquirer everypredetermined period; wherein the determiner presumes the position ofthe intersection outside the display screen based on the coordinates ofthe preceding intersection acquired by the intersection positionacquirer and stored in the storage unit if the determiner determinesthat the intersection is located outside the display screen of thedisplay unit and if the intersection position acquirer has not been ableto acquire the coordinates of the intersection, wherein the firstnotification controller notifies, through the first notifier, theposition of the intersection located outside the display screen with thefirst notifier and presumed by the determiner.
 5. The displaycontrolling device according to claim 2, wherein the virtual planeoutside the display screen is divided into a plurality of small regions,wherein the first notification controller includes: a judgment unit forjudging which one of the plurality the small regions the coordinates ofthe intersection acquired by the intersection position acquirer arelocated in; and an image displayer for memorizing information indicatingthe position of the intersection corresponding to each of the smallregions, determining information corresponding to a judgment result ofthe judgment unit from the information, and displaying determinedinformation on the display screen of the display unit.
 6. The displaycontrolling device according to claim 2, wherein the virtual planeoutside the display screen is divided into two large regions outwardlyof the screen, and the intersection position acquirer cannot acquire thecoordinates of the intersection in one region outside, and the otherregion inside is divided into a plurality of regions, and the virtualplane inside the display screen is divided into a plurality of smallregions, wherein the intersection position acquirer acquires thecoordinates of the intersection as information about the position of theintersection if the intersection is located in the other region inside,and acquires that there are no coordinates of the intersection asinformation about the position of the intersection if the intersectionis located in the one region outside, wherein the first notificationcontroller including: a storage unit for storing information about theposition of the intersection acquired by the intersection positionacquirer every predetermined period; a judgment unit for judging whichone of the plurality of the small regions in the other regions insidethe intersection is located in based on the coordinates if theinformation about the position of the intersection acquired by theintersection position acquirer is the coordinates of intersection, andfor judging which one of the plurality of small regions in the otherregion inside and the plurality of small regions inside the displayscreen the intersection is located in based on the coordinates of thepreceding intersection acquired by the intersection position acquirerand stored in the storage unit if the information about the position ofthe intersection is that there are no coordinates of the intersection;and an image displayer for memorizing information indicating theposition of the intersection corresponding to each of the small regions,determining the information corresponding to a judgment result of thejudgment unit from the information, and displaying determinedinformation on the display screen of the display unit.
 7. The displaycontrolling device according to claim 5, wherein the image displayer hasa table in which icons corresponding to each of the small regions areset, and determines an icon corresponding to the judgment result of thejudgment unit with reference to the table, and displays the icon at aprescribed position on the display screen of the display unit.
 8. Thedisplay controlling device according to claim 7, wherein displaypositions on the display screen of the display unit corresponding toeach of the small regions are set in the table, wherein the imagedisplayer displays the icon at the display position corresponding to thejudgment result of the judgment unit set in the table as the prescribedposition.
 9. The display controlling device according to claim 5,wherein the small regions includes at least eight regions each locatedin one of up, down, right, left, right oblique and left obliquedirections.
 10. The display controlling device according to claim 4,further comprising a time measurer for measuring time period duringwhich the intersection position acquirer is not able to acquire thecoordinates of the intersection; and a second notification controllerfor notifying that the position of the cursor is unclear with a secondnotifier if a time period measured by the time measurer become longerthan a prescribed time period.
 11. A program driving a computer providedwith a display device to function as: an input unit at which a signal isinput, the signal being output from an operation unit, the operationunit including an imaging sensor for capturing a light image, the signalbeing based on an image captured by the imaging sensor, the operationunit being arranged for a user to hold and operate, the light imagebeing emitted from a light emitter toward front of a display screen ofthe display device, the light emitter being provided in a periphery ofthe display screen; an intersection position acquirer for acquiring,every predetermined period, information about a position of anintersection based on the signal input at the input unit, theintersection being produced by a plane including the display screen ofthe display device and one of a region including an optical axis of theimaging sensor and a region including an axis substantially parallel tothe optical axis; a determiner for determining, every predeterminedperiod, whether the intersection is located inside the display screen ofthe display device based on the information about the position of theintersection acquired by the intersection position acquirer; a cursordisplayer for displaying a cursor at the position of the intersection onthe display screen of the display device if the determiner determinesthat the intersection is located inside the display screen; and a firstnotification controller for notifying that the cursor is located outsidethe display screen with a first notifier if the determiner determinesthat the intersection is not located inside the display screen.
 12. Theprogram according to claim 11, wherein the intersection positionacquirer has an orthogonal coordinate system defined in a virtual planeincluding the display screen, and acquires coordinates of theintersection in the orthogonal coordinate system as information aboutthe position of the intersection; wherein the determiner determineswhether the intersection is located inside the display screen of thedisplay device using the coordinates of the intersection acquired by theintersection position acquirer.
 13. The program according to claim 12,wherein the intersection position acquirer can acquire the coordinatesof the intersection in a prescribed region outside the display screen inthe virtual plane; wherein the determiner acquires the position of theintersection outside the display screen using the coordinates of theintersection acquired by the intersection position acquirer if thedeterminer determines that the intersection is located outside thedisplay screen of the display device; wherein the first notificationcontroller notifies the position of the intersection outside the displayscreen acquired by the determiner with the first notifier.
 14. Theprogram according to claim 12, further driving the computer to functionas a storage unit for storing information about the position of theintersection acquired by the intersection position acquirer; wherein thedeterminer presumes the position of the intersection outside the displayscreen based on the coordinates of the preceding intersection acquiredby the intersection position acquirer and stored in the storage unit ifthe determiner determines that the intersection is located outside thedisplay screen of the display unit and if the intersection positionacquirer has not been able to acquire the coordinates of theintersection, wherein the first notification controller notifies theposition of the intersection outside the display screen with the firstnotifier, the position being presumed by the determiner.
 15. The programaccording to claim 12, wherein the virtual plane outside the displayscreen is divided into a plurality of small regions, wherein the firstnotification controller includes: a judgment unit for judging which oneof the plurality the small regions the coordinates of the intersectionacquired by the intersection position acquirer are located in; and animage displayer for memorizing information indicating the position ofthe intersection corresponding to each of the small regions, determininginformation corresponding to a judgment result of the judgment unit fromthe information, and displaying determined information on the displayscreen of the display device.
 16. The program according to claim 12,wherein the virtual plane outside the display screen is divided into twolarge regions outwardly of the screen, and the intersection positionacquirer cannot acquire the coordinates of the intersection in oneregion outside, and the other region inside is divided into a pluralityof regions, and the virtual plane inside the display screen is dividedinto a plurality of small regions, wherein the intersection positionacquirer acquires the coordinates of the intersection as informationabout the position of the intersection if the intersection is located inthe other region inside, and acquires that there are no coordinates ofthe intersection as information about the position of the intersectionif the intersection is located in the one region outside, wherein thefirst notification controller including: a storage unit for storinginformation about the position of the intersection acquired by theintersection position acquirer every predetermined period; a judgmentunit for judging which one of the plurality of the small regions in theother regions inside the intersection is located in based on thecoordinates if the information about the position of the intersectionacquired by the intersection position acquirer is the coordinates ofintersection, and for judging which one of the plurality of smallregions in the other region inside and the plurality of small regionsinside the display screen the intersection is located in based on thecoordinates of the preceding intersection acquired by the intersectionposition acquirer and stored in the storage unit if the informationabout the position of the intersection is that there are no coordinatesof the intersection; and an image displayer for memorizing informationindicating the position of the intersection corresponding to each of thesmall regions, determining the information corresponding to a judgmentresult of the judgment unit from the information, and displayingdetermined information on the display screen of the display device. 17.The program according to claim 15, wherein the image displayer has atable in which icons corresponding to each of the small regions are set,and determines an icon corresponding to the judgment result of thejudgment unit with reference to the table, and displays the icon at aprescribed position on the display screen of the display device.
 18. Theprogram according to claim 17, wherein display positions on the displayscreen of the display device corresponding to each of the small regionsare set in the table, wherein the image displayer displays the icon atthe display position corresponding to the judgment result of thejudgment unit set in the table as the prescribed position.
 19. Theprogram according to claim 15, wherein the small regions includes atleast eight regions each located in one of up, down, right, left, rightoblique and left oblique directions.
 20. The program according to claim14, driving the computer to further function as a time measurer formeasuring time period during which the intersection position acquirer isnot able to acquire the coordinates of the intersection; and a secondnotification controller for notifying that the position of the cursor isunclear with a second notifier if a time period measured by the timemeasurer become longer than a prescribed time period.
 21. A recordingmedium storing the program according to claim 11, the recording mediumbeing readable by a computer.